1. Field of the Invention
The present invention relates to a document verification system, a document verification method, an information registration device, a recording medium having an information registration instruction recorded thereon, a document verification device, a recording medium having a document verification instruction recorded thereon, and a document verification database. In particular, the invention relates to a document verification system and a document verification method for verifying whether or not a document is the original, an information registration device used in the document verification system, a recording medium having an information registration instruction recorded thereon, a document verification device, a recording medium having a document verification instruction recorded thereon, and a document verification database.
2. Description of the Related Art
In order to prevent counterfeiting, it is necessary to conduct special processes on a document, which has value in being original, such as paper documents like securities, various certificates of title, insurance policies, resident cards, birth certificates, written guarantees, passports, bank bills and secret papers, and ID cards.
Conventionally, therefore, there are techniques for counterfeit prevention using special paper and printing a mark or a pattern in a note issue system using a facsimile machine (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 5-101089), techniques of using special magnetic ink for preventing counterfeit using a copying machine (see, for example, JP-A No. 2000-95982), techniques of mixing a document with an optical semiconductor for preventing counterfeit (reproduction) of a bill or a security (see, for example, JP-A No. 8-241451), and techniques of embedding invisible information by using special halftone printing (see, for example, JP-A No. 11-261806).
On the other hand, in a highly information-oriented society, a situation in which content contained in the above described various documents is electronized (namely, processed so as to be usable by a computer and the like), printed and utilized is imagined. Therefore, it is thought that a situation in which an ordinary user gets the electronized content via a network such as the Internet, prints the electronized content by using an arbitrary printer, and uses the printed matter as a security or a certificate document, will increase. Therefore, it is expected that in the near future a technique, with which it can be verified with certainty whether a document printed by a printer is the original, will be demanded.
Therefore, applying each of the techniques described in JP-A Nos. 5-101089, 2000-95982, 8-241451, and 11-261806 as the above-mentioned techniques have been considered. In other words, when the technique described in JP-A No. 5-101089 is applied, whether a document is the original or not is verified on the basis of the kind of paper used for the document to be verified or the state of the printed mark or pattern. When the technique described in JP-A No. 2000-95982 is applied, whether a document is the original or not is verified on the basis of the state of magnetic ink used for printing. When the technique described in JP-A No. 8-241451 is applied, whether a document is the original or not is verified on the basis of whether there is an optical semiconductor mixed with the document. When the technique described in JP-A No. 11-261806 is applied, whether a document is the original or not is verified on the basis of the state of the embedded invisible information.
However, when each of the techniques described in JP-A Nos. 5-101089, 2000-95982, 8-241451, and 11-261806 is applied in order to verify whether a document printed by a printer is the original, it is necessary to conduct special processing on a document to be verified and this results in the problems of high cost and complicated processing.